Atrazine, spring burning, and nitrogen for improvement of tallgrass prairie

• Published in: Journal of range management 1987-09, Vol.40 (5), p.444-447
• Main Authors: Gillen, R.L, Rollins, D, Stritzke, J.F
• Format: Article
• Language: English
• Subjects: Agricultural management; AMELIORATION DES PATURAGES; APLICACION DE FERTILIZANTES; AZOTE; BOTANICAL COMPOSITION; BRULAGE DIRIGE; COMPOSICION BOTANICA; COMPOSITION BOTANIQUE; CONTROLLED BURNING; ECOLOGICAL SUCCESSION; Ecology; FERTILISATION; Fertilization; FERTILIZER APPLICATION; Forbs; GRAMINEAE; Grasses; HERBICIDAS; HERBICIDE; HERBICIDES; MEJORA DE PASTIZALES; NITROGEN; NITROGENO; OKLAHOMA; PASTURE IMPROVEMENT; Perennials; PRADERAS DE AMERICA DEL NORTE; PRAIRIE; PRAIRIES; QUEMA CONTROLADA; Range management; SUCCESSION ECOLOGIQUE; SUCESION ECOLOGICA; Tallgrass prairies; Vegetation
• ISSN: 0022-409X; 2162-2728
• DOI: 10.2307/3899608

Spring application of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] (1.1 kg ha-1a.i.), burning, and nitrogen (33 kg ha-1as ammonium nitrate) were evaluated alone and in all combinations for improvement of mid-seral tallgrass prairie in northcentral Oklahoma. Studies were initiated in 1984 (Study I) and 1985 (Study II). Precipitation and successional status of the vegetation at treatment application were higher for Study II than for Study I. Atrazine effectively reduced forbs and annual grasses for 2 years after application. Atrazine stimulated warm-season perennial grasses but did not generally increase total herbage production. Burning was similar to atrazine for annual grass control in both studies. Burning was also similar to atrazine for forb control in Study I but had no impact on forb production in Study II. Burning increased perennial grass production only in the second year of Study I. Burning decreased total herbage production in the first year of Study I by reducing annual grasses and forbs but did not affect total herbage production on other dates. Nitrogen did not consistently increase perennial grass production but did increase forb production by 250-300% when applied alone. Both atrazine and burning rapidly shifted species composition in favor of desirable perennial grasses. Nitrogen was not as effective in changing species composition either alone or in combination with atrazine and burning. The number and complexity of treatment responses declined as successional status and/or precipitation improved.